Disable synchronous writes to the master journal when PRAGMA synchronous=OFF

for all database files.  Ticket #1375. (CVS 2630)

FossilOrigin-Name: 644b96aa23de7e828280d35785db840a4fa9413d

manifest

@@ -1,5 +1,5 @@
-C Fix\scomment\sin\svdbeapi.c.\s\sRemove\sunused\sstructure\sdefinition\sfrom\sfunc.c.\s(CVS\s2629)
-D 2005-08-27T13:16:33
+C Disable\ssynchronous\swrites\sto\sthe\smaster\sjournal\swhen\sPRAGMA\ssynchronous=OFF\nfor\sall\sdatabase\sfiles.\s\sTicket\s#1375.\s(CVS\s2630)
+D 2005-08-27T16:36:49
 F Makefile.in 12784cdce5ffc8dfb707300c34e4f1eb3b8a14f1
 F Makefile.linux-gcc 06be33b2a9ad4f005a5f42b22c4a19dab3cbb5c7
 F README 9c4e2d6706bdcc3efdd773ce752a8cdab4f90028
@@ -32,8 +32,8 @@ F src/alter.c 26d755f2143719dd3f5b8aaf6cbe3c7f95332528
 F src/analyze.c 3ab32927f4d3067ead10e4c4f6fb61b2a93479cc
 F src/attach.c 4b21689700a72ae281fa85dbaff06b2a62bd49ee
 F src/auth.c 31e2304bef67f44d635655f44234387ea7d21454
-F src/btree.c 667227e4375d8bf6abd748cf6bad7a2004bf5d87
-F src/btree.h 41a71ce027db9ddee72cb43df2316bbe3a1d92af
+F src/btree.c 5b3bc015c49a41c025cfdf8ad36051f3007e2cb0
+F src/btree.h 1ed561263ca0e335bc3e81d761c9d5ff8c22f61e
 F src/build.c 55e7e915a538bb25b1b7448cfb9189cccba554b2
 F src/callback.c 9a1162c8f9dae9fad6d548339669aacb5f6cf76b
 F src/complete.c 4de937dfdd4c79a501772ab2035b26082f337a79
@@ -56,8 +56,8 @@ F src/os_unix.c 7fae44e25c6137340b786b83ecb29db6ba525a64
 F src/os_unix.h 5768d56d28240d3fe4537fac08cc85e4fb52279e
 F src/os_win.c fe7b99cfcfb61d9bf54493ddf5857885a657fb89
 F src/os_win.h 41a946bea10f61c158ce8645e7646b29d44f122b
-F src/pager.c 4c6c6a553d6d23ff6a3a50df5fe53f730f3e387f
-F src/pager.h 0d9153d6269d60d04af3dd84a0cc0a96253cf4a4
+F src/pager.c cd9896287a8fd33cc267bd0c2b69c421a4808169
+F src/pager.h 17b13225abd93c1e9f470060f40a21b9edb5a164
 F src/parse.y d57cdd2adc0923762b40314f08683c836a2e0c90
 F src/pragma.c 69413fbdc0c6aaa493a776ea52c1b3e6cf35dfb2
 F src/prepare.c 86f0d8e744b8d956eff6bc40e29049efee017610
@@ -84,7 +84,7 @@ F src/vdbe.c 69f33e22c7d0a64b23fbb69e6da95a1bb6869032
 F src/vdbe.h 3b29a9af6c7a64ed692bef1fc5f61338f40d2f67
 F src/vdbeInt.h 89a7fa5dc35477bd30ea27b0bf38e9e5c2903812
 F src/vdbeapi.c f1adebb5e3fe4724ed0e1a82c4a61809d7e15e9e
-F src/vdbeaux.c 874624698fad54a59c6a0bcccea9d5aaa8655ab6
+F src/vdbeaux.c ae051fd18bd2fc642910fbc95d6763d730936511
 F src/vdbefifo.c 9efb94c8c3f4c979ebd0028219483f88e57584f5
 F src/vdbemem.c 4732fd4d1a75dc38549493d7f9a81d02bf7c59b5
 F src/where.c 485041aa51fb33f43b346e018f7c01422847f364
@@ -207,6 +207,7 @@ F test/select7.test 1bf795b948c133a15a2a5e99d3270e652ec58ce6
 F test/sort.test 3b871d6e032f0a6c84d9f3d2d4b226e8fda97de0
 F test/subquery.test ed4ecba1afacb586c86fad1cdb92756a48a90302
 F test/subselect.test 3f3f7a940dc3195c3139f4d530385cb54665d614
+F test/sync.test d769caaec48456119316775e35e0fdee2fa852d7
 F test/table.test d0e05ede3f6e5a8b79f8661ddcc4618cf7e69f8a
 F test/tableapi.test 6a66d58b37d46dc0f2b3c7d4bd2617d209399bd1
 F test/tclsqlite.test a8d9afe680c466881a40252a86ef0fca457ab08c
@@ -298,7 +299,7 @@ F www/tclsqlite.tcl 3df553505b6efcad08f91e9b975deb2e6c9bb955
 F www/vdbe.tcl 87a31ace769f20d3627a64fa1fade7fed47b90d0
 F www/version3.tcl a99cf5f6d8bd4d5537584a2b342f0fb9fa601d8b
 F www/whentouse.tcl 97e2b5cd296f7d8057e11f44427dea8a4c2db513
-P ecb9604457d5ab6bcd81b582cc4dd85a8f371b86
-R bbe29a50d2da25ad59c230f05a2f2f4d
+P 51a381345db45967567dd0a18905d352bf1081e0
+R 4f5f18e550ba91f695166764c512671e
 U drh
-Z 787ff796a6044c29e432aa2a25d2214c
+Z d452b4201f127e09042815840df7485c

manifest.uuid

@@ -1 +1 @@
-51a381345db45967567dd0a18905d352bf1081e0
+644b96aa23de7e828280d35785db840a4fa9413d

src/btree.c

@@ -9,7 +9,7 @@
 **    May you share freely, never taking more than you give.
 **
 *************************************************************************
-** $Id: btree.c,v 1.264 2005/08/02 17:13:10 drh Exp $
+** $Id: btree.c,v 1.265 2005/08/27 16:36:49 drh Exp $
 **
 ** This file implements a external (disk-based) database using BTrees.
 ** For a detailed discussion of BTrees, refer to
@@ -1345,6 +1345,15 @@ int sqlite3BtreeSetSafetyLevel(Btree *pBt, int level){
 }
 #endif
 
+/*
+** Return TRUE if the given btree is set to safety level 1.  In other
+** words, return TRUE if no sync() occurs on the disk files.
+*/
+int sqlite3BtreeSyncDisabled(Btree *pBt){
+  assert( pBt && pBt->pPager );
+  return sqlite3pager_nosync(pBt->pPager);
+}
+
 #if !defined(SQLITE_OMIT_PAGER_PRAGMAS) || !defined(SQLITE_OMIT_VACUUM)
 /*
 ** Change the default pages size and the number of reserved bytes per page.

src/btree.h

@@ -13,7 +13,7 @@
 ** subsystem.  See comments in the source code for a detailed description
 ** of what each interface routine does.
 **
-** @(#) $Id: btree.h,v 1.63 2005/03/21 04:04:03 danielk1977 Exp $
+** @(#) $Id: btree.h,v 1.64 2005/08/27 16:36:49 drh Exp $
 */
 #ifndef _BTREE_H_
 #define _BTREE_H_
@@ -58,6 +58,7 @@ int sqlite3BtreeClose(Btree*);
 int sqlite3BtreeSetBusyHandler(Btree*,BusyHandler*);
 int sqlite3BtreeSetCacheSize(Btree*,int);
 int sqlite3BtreeSetSafetyLevel(Btree*,int);
+int sqlite3BtreeSyncDisabled(Btree*);
 int sqlite3BtreeSetPageSize(Btree*,int,int);
 int sqlite3BtreeGetPageSize(Btree*);
 int sqlite3BtreeGetReserve(Btree*);

src/pager.c

@@ -18,7 +18,7 @@
 ** file simultaneously, or one process from reading the database while
 ** another is writing.
 **
-** @(#) $Id: pager.c,v 1.209 2005/08/21 16:54:25 drh Exp $
+** @(#) $Id: pager.c,v 1.210 2005/08/27 16:36:49 drh Exp $
 */
 #ifndef SQLITE_OMIT_DISKIO
 #include "sqliteInt.h"
@@ -779,7 +779,7 @@ static int writeMasterJournal(Pager *pPager, const char *zMaster){
   if( rc!=SQLITE_OK ) return rc;
 
   rc = sqlite3OsWrite(&pPager->jfd, aJournalMagic, sizeof(aJournalMagic));
-  pPager->needSync = 1;
+  pPager->needSync = !pPager->noSync;
   return rc;
 }
 
@@ -3345,6 +3345,14 @@ const char *sqlite3pager_journalname(Pager *pPager){
   return pPager->zJournal;
 }
 
+/*
+** Return true if fsync() calls are disabled for this pager.  Return FALSE
+** if fsync()s are executed normally.
+*/
+int sqlite3pager_nosync(Pager *pPager){
+  return pPager->noSync;
+}
+
 /*
 ** Set the codec for this pager
 */

src/pager.h

@@ -13,7 +13,7 @@
 ** subsystem.  The page cache subsystem reads and writes a file a page
 ** at a time and provides a journal for rollback.
 **
-** @(#) $Id: pager.h,v 1.44 2005/05/20 20:01:56 drh Exp $
+** @(#) $Id: pager.h,v 1.45 2005/08/27 16:36:49 drh Exp $
 */
 
 /*
@@ -100,6 +100,7 @@ void sqlite3pager_set_safety_level(Pager*,int);
 const char *sqlite3pager_filename(Pager*);
 const char *sqlite3pager_dirname(Pager*);
 const char *sqlite3pager_journalname(Pager*);
+int sqlite3pager_nosync(Pager*);
 int sqlite3pager_rename(Pager*, const char *zNewName);
 void sqlite3pager_set_codec(Pager*,void(*)(void*,void*,Pgno,int),void*);
 int sqlite3pager_movepage(Pager*,void*,Pgno);

src/vdbeaux.c

@@ -1090,6 +1090,7 @@ static int vdbeCommit(sqlite3 *db){
   */
 #ifndef SQLITE_OMIT_DISKIO
   else{
+    int needSync = 0;
     char *zMaster = 0;   /* File-name for the master journal */
     char const *zMainFile = sqlite3BtreeGetFilename(db->aDb[0].pBt);
     OsFile master;
@@ -1125,6 +1126,9 @@ static int vdbeCommit(sqlite3 *db){
       if( pBt && sqlite3BtreeIsInTrans(pBt) ){
         char const *zFile = sqlite3BtreeGetJournalname(pBt);
         if( zFile[0]==0 ) continue;  /* Ignore :memory: databases */
+        if( !needSync && !sqlite3BtreeSyncDisabled(pBt) ){
+          needSync = 1;
+        }
         rc = sqlite3OsWrite(&master, zFile, strlen(zFile)+1);
         if( rc!=SQLITE_OK ){
           sqlite3OsClose(&master);
@@ -1141,7 +1145,7 @@ static int vdbeCommit(sqlite3 *db){
     */
     zMainFile = sqlite3BtreeGetDirname(db->aDb[0].pBt);
     rc = sqlite3OsOpenDirectory(zMainFile, &master);
-    if( rc!=SQLITE_OK || (rc = sqlite3OsSync(&master))!=SQLITE_OK ){
+    if( rc!=SQLITE_OK || (needSync && (rc=sqlite3OsSync(&master))!=SQLITE_OK) ){
       sqlite3OsClose(&master);
       sqlite3OsDelete(zMaster);
       sqliteFree(zMaster);

test/sync.test

@@ -0,0 +1,81 @@
+# 2005 August 28
+#
+# The author disclaims copyright to this source code.  In place of
+# a legal notice, here is a blessing:
+#
+#    May you do good and not evil.
+#    May you find forgiveness for yourself and forgive others.
+#    May you share freely, never taking more than you give.
+#
+#***********************************************************************
+# This file implements regression tests for SQLite library.
+#
+# This file implements tests to verify that fsync is disabled when
+# pragma synchronous=off even for multi-database commits.
+#
+# $Id: sync.test,v 1.1 2005/08/27 16:36:49 drh Exp $
+
+set testdir [file dirname $argv0]
+source $testdir/tester.tcl
+
+#
+# These tests are only applicable on unix when pager pragma are
+# enabled.
+#
+if {$::tcl_platform(platform)!="unix"} {
+  finish_test
+}
+ifcapable !pager_pragmas {
+  finish_test
+}
+
+do_test sync-1.1 {
+  set sqlite_sync_count 0
+  file delete -force test2.db
+  file delete -force test2.db-journal
+  execsql {
+    CREATE TABLE t1(a,b);
+    ATTACH DATABASE 'test2.db' AS db2;
+    CREATE TABLE db2.t2(x,y);
+  }
+  set sqlite_sync_count
+} 8
+do_test sync-1.2 {
+  set sqlite_sync_count 0
+  execsql {
+    PRAGMA main.synchronous=on;
+    PRAGMA db2.synchronous=on;
+    BEGIN;
+    INSERT INTO t1 VALUES(1,2);
+    INSERT INTO t2 VALUES(3,4);
+    COMMIT;
+  }
+  set sqlite_sync_count
+} 8
+do_test sync-1.3 {
+  set sqlite_sync_count 0
+  execsql {
+    PRAGMA main.synchronous=full;
+    PRAGMA db2.synchronous=full;
+    BEGIN;
+    INSERT INTO t1 VALUES(3,4);
+    INSERT INTO t2 VALUES(5,6);
+    COMMIT;
+  }
+  set sqlite_sync_count
+} 10
+do_test sync-1.4 {
+  set sqlite_sync_count 0
+  execsql {
+    PRAGMA main.synchronous=off;
+    PRAGMA db2.synchronous=off;
+    BEGIN;
+    INSERT INTO t1 VALUES(5,6);
+    INSERT INTO t2 VALUES(7,8);
+    COMMIT;
+  }
+  set sqlite_sync_count
+} 0
+
+
+finish_test